Stereoscope apparatus



1940- L. w. WALTER 2,187,765

STEREOSCOPE APPARATUS Filed July 20, 1936 2 Sheets-Sheet 1 Louzls Wl Valzer Jan. 23, 1940. w. WALTER smznnoscon: APPARATUS Filed July 20, 1936 2 Sheets-Sheet 2 fizz/an er" Louis WI VaZer Patented Jan. 23, 1940 2,187,785 I STEREOSCOPE ArrAnA'rUs Louis W. Walter, Chicago, m." A plication July 20, 1936, Serial No. 91,50:

6 Claims.

The invention relates to stereoscope apparatus.

The primary object of the invention is to provide a simple and improved stereoscope so constructed that it may be readily disassembled or collapsed into the form of a compact package.

A more specific object of the invention is to provide an improved form of stereoscope constructed from portions of sheet material such as cardboard and so'designed that it may be readily disassembled or collapsed and all parts disposed in flat face-to-face contact to facilitate the packaging thereof in an ordinary envelope.

Since stereoscopes made in accordance with the present invention can be manufactured at very low cost and packaged in convenient form, they constitute an especially attractive form of advertising medium. That is, these improved stereoscopes may, for example, be given away as premiums or sold for a nominal sum by manufacturers of some product to be advertised. The novelty of the device lends it particular attraction. Also, pictures to be used with the stereoscope may be furnished by the manufacturer at regular intervals in order to stimulate a continued interest in his product. Such pictures can be reproduced most readily either individually or as a part of the manufacturers ordinary advertisements in periodicals by the well-known half-tone printing process. Such half-tone prints are constituted by a series of closely spaced tiny dots. The cost of the prints depends in a large measure on the size and spacing of the dots used.

Another object of the present invention is to provide an improved stereoscope particularly adapted for use in viewing pictures made by the half-tone printing process of such character that any unpleasant or unreal effect due to magnification of the individual dots forming the picture is avoided.

Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the accompanying drawings in which,

Figure 1 is a perspective view of a stereoscope, embodying the present invention.

Fig. 2 is a transverse sectional view along the line 2-2 in Fig. 1.

Fig. 3 is a detail plan view on reduced scale of the viewing mask included in the stereoscope shown in Fig. 1.

Fig. 3'- is a fragmentary detail view of an alternative form of lens mounting.

Fig. 4 is a detail plan view on reduced scale of 6 the picture support included in the stereoscope shown in Fig. 1.

Fig. 5 is a detail plan view on reduced scale of the frame included in Fig. 1, the frame being shown as unfolded in flat form.

Figs. 6 and 7 are detail plan views of the longitudinal partition and cross braces, respectively, of the stereoscope shown in Fig. 1.

Fig. 8 is a diagrammatic representation of the optical system of the stereoscope in Fig. 1.

Fig. 9 is a perspective view of a modified form of stereoscope, embodying the invention.

Fig. 10 is a transverse sectional view along the line I0l0 in Fig. 9.

Fig. 11 is a detail plan view on reduced scale 20 of the frame included in the stereoscope shown in Fig. 9, the frame being illustrated in its unfolded position.

Figs. 12, 13, 14 and 15 are detail plan views on reduced scale of the picture support, viewing 25 mask, longitudinal partition, and one of the cross braces included in the stereoscope shown in Fig. 9.

Referring more particularly to the drawings, a particular embodiment of the invention has been shown in the form of a stereoscope in Fig. 1 for purposes of illustration. In general, the principal parts of the stereoscope illustrated are made of some sheet material, such as cardboard, and are so arranged that the entire device may be disassembled or collapsed into the form of a flat mailable package.

The particular stereoscope shown in Fig. 1 includes a longitudinally elongated channel-shaped frame l0 made of cardboard or other readily foldable sheet material. This portion of sheet 40 material is scored longitudinally as indicated at H and I2 (Fig. 5) in order that the side portions I3 and 14 thereof may be bent upwardly to give the frame a generally U-shaped cross section as shown in Fig. 1. The side portions l3 and I4 of 45 the frame are held in their folded or bent position by cross braces 15. These cross braces are disposed in slots l6 formed in the side walls or members of the frame I'll, the cross braces being provided with slots l'l engaging the adjacent side 50 walls of the frame when the cross braces are positioned thereon. It will thus be seen that when the cross braces l5 are positioned on the channel-shaped frame Ill as shown in Fig. 1, the cross braces and side walls of the frame are dis- 5:;

posed in intersecting relation, thus forming a rigid, grid-like, supporting structure.

A viewing mask is disposed at the front end of the frame 10, this mask also being formed from a fiat portion of sheet material. In the construction illustrated in Fig. 1, the viewing mask I8 is formed from a substantially circular portion of cardboard and has a pair of transversely alined apertures is formed therein. These apertures are spaced apart approximately the distance between a normal pair of human eyes so that the user may look through the same and view the pictures mounted at the rear end of the frame 10 as is hereinafter described. An elongated aperture 20 is also preferably formed in the mask l8 to accommodate the user's nose. A pair of suitable magnifying lenses 2| are mounted in the apertures i9, this mounting being preferably effected by press fitting the same in the apertures formed in the yieldable sheet material. The mounting may alternatively be effected by securing the lenses in place by suitable cementitious adhesive, or by circular strips of adhesive tape 2| surrounding the edge portions thereof as shown in Fig. 3. The mask i8 is detachably mounted on the front end portion of the frame in and transversely with respect thereto by cooperating slots 22 and 23 formed in the mask and frame, respectively.

A pair of stereoscopic pictures 24 to be viewed are mounted at the rear end of the frame ID in alinement with the apertures IS, the pictures being preferably printed on a single sheet of paper. A circular picture support 25 also formed from a flat portion of sheet material such as cardboard, is preferably detachably mounted on the rear end portion of the frame ID. A pair of slots 26 is formed in the lower edge of the picture support 25 and fits over the adjacent side walls of the base frame l0. Complementary slots 21 in the rear end of the frame engage the picture support 25, the picture support and the frame being disposed in intersecting relationship.

A longitudinally extending partition 28 is detachably mounted on the frame l0 and serves to segregate the view had through each of the apertures l9 as well as to hold the pictures 24 in place on the picture support 25. The partition 28 is provided with downwardly extending projections 29 having slots 30 formed therein which fit over the central portions of the cross braces [5. The rear end of the longitudinal partition 28 is arranged to bear against the center portion of the pictures 24 so as to press the same against the picture support 25. An offset 3| is formed in the front edge of the partition 28 in order to form a nose space behind the aperture 20 in the viewing mask I8.

From the foregoing it will be seen that all of the structural elements of the stereoscope shown in Fig. 1 may be formed from cardboard or the like by very simple and economical punch press methods. In addition, when the individual elements are separated they are all of fiat form or configuration. Consequently, they may be stacked in face-to-face relation and inserted in an ordinary envelope thus forming a flat compact mailable package, particularly adapted for use by an advertiser.

In assembling the device, the side portions l3 and I4 of the frame In are bent upwardly to give it a channel-shaped form. The cross braces I5 are put in place, to hold the frame in its assembled shape. Then the viewing mask i8 and picture support 25 are put in place, thus completing the assembly. The space between the respective side walls I3 and I4 and the center portion 23 form convenient pockets for storing extra pictures 24'.

It is desirable to form the pictures 24 and 24- by a half-tone printing process so that they may be incorporated as part of an advertisement in a periodical. Most half-tone prints in magazines, for example, are formed by dots arranged about 92 to the inch. The stereoscope apparatus should, however, be arranged so that when the small pictures are magnified thereby an unpleasant magnification of the individual dots will not result. In general, it has been found that the angle subtended by the virtual image of the dots should not exceed 0 10' if objectionable individuality of the dots in the picture is to be avoided. Thus, referring to Fig. 8, the arrow 32 represents in exaggerated form one dot on the picture 24. The arrow 33 represents the virtual image of the arrow 32 as it appears to an observer's eye located at F on the opposite side of the converging lens 2|. Then the angle a subtended by the imagev 33 must be less than 0 10' to obviate objectionable dot magnification.

There are other structural limitations of the apparatus which further complicate the problem, however. The length of a stereoscope of the type contemplated is limited by the necessity of having it of minimum size and weight. For this reason, the distance D from lens to picture should not be more than about 12 inches. If an object is held closer than about 10 inches from the eye, however, it becomes indistinct so that a magnifying lens must be used. On the other hand, if the distance b is less than about 4 inches, the magnification is much higher and consequently, much smaller dots must be used in the halftone print, thereby greatly increasing their cost. It has been found that satisfactory results are had by making the distance b about 6% inches and using plano-convex lenses with a radius of 124 centimeters when using half-tone prints with about 92 dots per inch.

A modified form of stereoscope embodying the invention is illustrated in Fig. 9. This stereoscope is similar to that shown in Fig. 1 in that it may be disassembled or collapsed to form a compact fiat package. It includes a longitudinally elongated channel-shaped frame 34 preferably made of two sheets of cardboard 35 and 36 disposed in overlapping relation and secured together by staples 31. These sheets are scored longitudinally as indicated at 38 and 39 (Fig. 11) in order that the side portions thereof may be bent upwardly to give the frame a generally U-shaped cross section. Cross braces 40 are disposed in intersecting relationship with the side walls of the frame, the cross braces and frame being provided with complementary slots 4| and 42, respectively, for this purpose. A rigid gridlike structure is thus formed which constitutes a highly stable base for the device.

A viewing mask 43 is disposed at the front end of the frame 34, this mask also being formed from a flat portion of sheet material. The viewing mask 43 is substantially circular in shape with a straight lower edge 44 adapted to bear against the bottomwall of the frame 34 when in position thereon. Complementary slots 45 and 46 formed in the mask 43 and frame 34, respectively, serve to secure the mask detachably in position. A pair of apertures 41 in the mask 43 support magnifiying lenses 48 which are preferably press fitted therein, the apertures being spaced apart aparomas mal human eyes. An elongated aperture 48 accomodates the user's nose.

The lenses 48 are preferably converging lenses of piano-convex construction. Also, their power of magnification is preferably so related to the distance between the same and a picture viewed thereby that the virtual image of individual halftone dots in a half-tone print will subtend an angle of less than A pair of -stereoscopic pictures 50 to be viewed are mounted at the rear end of the frame 34 in alinement with the apertures 41, the pictures being preferably printed o'n a single sheet of paper. A circular picture support 5i made of sheet material cooperates with a longitudinal partition 52 to hold the pictures in position there'- between. The support 5| is detachably mounted on the rear end of the frame 34 by means of complementary slots 53 and 5| formed, respectively, in the support and frame. The partition 52 is in turn detachably mounted on the frame by complementary slots 55 and 56 formed in the cross braces 40 and the partition, respectively.

An offset 52 in the front edge of the partition52 accommodates the users nose. The partition 52 also serves to segregate the view had from each of the apertures 41 so that the user views one picture with one eye and the other picture with the other eye, the two images being, in effect, superimposed to give an illusion of depth in the resulting composite image.

Upon reference to Figs. 12 and it will be seen that the lower portions of the picture sup. port 5| and cross braces are cut away as indicated at 51 and 58. A pocket or recess 59 (Fig. 10) is thus formed in which a reserve supply of pictures may conveniently be stored.

The stereoscope shown in Fig. 9 may be dis-' assembled into a plurality of flat portions of sheet material indicated in the several detail views. When these individual portions of sheet material are then stacked in superimposed relation they form a compact package of minimum size.

Although two particular embodiments of the invention have been shown and described for purposes of illustration there is no intention to thereby limit the invention to these particular embodiments, but on the other hand, the following claims are intended to cover all modifications within the spirit and scope of the invention.

I claim as my invention:

1. A stereoscope apparatus arranged for dis assembly into a plurality of portions of fiat sheet material readily adapted for disposition in a flat compact mailable package comprising, in combination, a generally channel-shaped portion of sheet material forming an elongated frame having -a U-shaped cross section, the side members of said frame having inwardly extending slots formed therein, cross braces formed from portions of sheet material having slots therein engaging the side members of said frame and disposed in the slots therein, an upright portion of sheet material disposed adjacent one end of said frame and extending transversely with respect thereto forming a viewing mask, said viewing mask having a pair of apertures therein spaced apart approximately the distance between a pair of normal human eyes, a second upright portion of sheet material disposed adjacent the opposite end of said'frame and forming a picture support in alinement with said apertures, and an upright partition of sheet material extending longitudinally of said frame between said mask and said picture supporasaid partition being detachably mounted in alined slots formed in the upper edges of said cross braces. 2. A stereoscope apparatus arranged for disassembly into a plurality of portions of fiat sheet material adapted for disposition in a flat compa'ct mailable package comprising, in combination, a rigid base structure embodying a plurality of longitudinally extending generally upright portions-of sheet material and a plurality of intersecting transversely extending generally upright portions of sheet material, both said longitudinal and transverse portions of sheet material having registering slots formed therein detachably receiving the adjacent portions of the intersecting members in the form of a grid to support the same against lateral displacement, said longitudinal portions of said sheet material being fashioned to support a picture to be viewed adjacent one end thereof, and an upright portion of sheet material disposed at the opposite end of said longitudinal portions of said sheet material and extending transversely with respect thereto, said last named portion of sheet material being apertured to form a viewing mask.

3. A stereoscope apparatus arranged for disassembly into a plurality of portions of flat sheet material readily adapated for disposition in a flat compact mailable package comprising, in combination, a generally channel-shaped portion of sheet material forming an elongated frame having a U-shaped cross section, the side members of said frame having inwardly extending slots formed adjacent the ends thereof, cross braces formed from portions of sheet material having slots therein engaging the side members of said frame and disposed in said slots therein, an upright portion of sheet material disposed adjacent one end of said frame and extending transversely with respect thereto forming a viewing mask, said viewing mask having a pair of apertures therein spaced apart approximately the distance between a pair of normal human eyes, a second upright portion of sheet material disposed adjacent the opposite end of said frame and forming a picture support in alinement with said apertures, an upright partition of sheet material extending longitudinally of said frame between said mask and said picture support, said partition being detachably mounted in alined slots formed in the upper edges of said cross braces, said crossbraces being spaced apart a suiiicient distance to form pockets between the adjacent side the side members of said frame and disposed in the slots therein, an upright portion of sheet material disposed adjacent one end of said frame and extending transversely with respect thereto forming a viewing mask, said viewing mask having a pair of apertures therein spaced apart approximately the distance between a pairof normal human eyes, a second upright portion of sheet material disposed adjacent the opposite end of said frame and forming a picture support 7 in alinement with said apertures, and an upright partition of sheet material extending longitudinally of said frame between said mask and said picture support, said partition being detachably mounted in alined slots formed in the upper edges of said cross braces, the lower edges of said cross braces being disposed in spaced relation with respect to the bottom wall of said frame to form a pocket therebetween adapted to receive a reserve supply of pictures.

5. A stereoscope apparatus arranged for disassembly into a plurality of portions of flat sheet material readily adapted for disposition in a flat compact mailable package comprising, in combination, longitudinally and transversely extending portions of sheet material having complementary slots therein, said portions of sheet material being arranged in intersecting relationship in a generally grid-like structure, an upright portion of sheet material removably secured to one end of said structure and extending transversely with respect thereto, said upright portion of sheet material having a pair of apertures therein spaced apart approximately the distance between a normal pair of human eyes and having a third aperture therein adapted to accommodate the user's nose, and a longitudinal partition located centrally of said structure behind said upright portion of sheet material and having an offset formed in the forward edge thereoi. ad- Jacent said third aperture. I

6. In a stereoscope, the combination of a pair oi transversely alined half-tone prints, a viewing mask, and a pair of converging lenses mounted on said mask in spaced relation, the power of magnification of said lenses being suillciently small as compared to the distance between the adjacent half-tone dots in the pictures that the virtual images of the individual dots forming the half-tone prints viewed subtend an angle of less than ten minutes at the point of observation when said lenses are located at their iocal distance from said prints.

LOUIS W. WALTER. 

